This story was initially printed in June 2020.
Mulching is a good way to suppress weeds, retain moisture and, relying on the substrate you select, add some vitamins again into the soil of your backyard plot. It doesn’t appear that tough to simply lay a bunch of wooden chips or newspaper over your plot, however there may be truly extra to it than that.
The truth is, many gardeners who’re utilizing mulch for the primary time make one deadly mistake that may render their mulch a lot much less efficient than it could be in any other case — they apply the improper thickness.
“When you pack [mulch] thick sufficient it makes an impermeable barrier for weeds,” stated Eric Gallandt, professor of weed ecology on the College of Maine. “One of many greatest issues for mulching gardens is that this skimp on it.”
Thickness actually issues. In relation to weed management, any mulch will be efficient so long as you place down a thick sufficient layer.
“If you unfold [mulch] out and it’s solely a pair inches thick it could look good but it surely compresses actually shortly,” Gallandt stated. “Anyplace you could have gaps in your mulch you’re going to have weeds coming by. You need to be sure you have your mulch layer a enough thickness in order for you it to stop weeds for the entire season.”
Matthew Wallhead, decorative horticulture specialist and assistant professor on the College of Maine Cooperative Extension, stated {that a} good rule of thumb is to have not less than two inches of mulch, however typically not more than six inches.
“Generally for sure conditions, for those who’re actually making an attempt to manage weeds, you may go to a deeper mulch,” Wallhead stated. “If it’s lower than 2 inches you’re in all probability not going to get enough weed management.”
Nonetheless, totally different mulches require totally different thicknesses. Sonja Birthisel, postdoctoral analysis affiliate on the College of Maine, stated that pure and natural mulches reminiscent of hay, straw or leaf litter will want an additional thick layer of mulch. Not solely will microbes within the soil eat away on the materials over the course of the season, however the once-fluffy materials additionally will shortly compress and depart gaps of uncovered soil.
“You want a fairly beefy 3 or 4 inches of mulch, notably for those who’re going to be utilizing hay or straw mulch so that you simply’re absolutely blocking that mild so weeds can’t come up,” Birthisel stated.
The identical goes for upcycled, DIY paper mulches.
“That newspaper goes to interrupt down faster than wooden or wooden chips,” Birthisel stated. “You’re going to need a number of inches of newspaper.”
The College of Maine Cooperative Extension gives a useful desk that guides gardeners by accumulating enough mulch to cowl the world and depth of their gardens. Wallhead added that backyard heart workers can assist you be sure you are buying sufficient mulch.
“Inform them what you’re doing, [ask] if they’ve any strategies and be sure you’re making use of a deep sufficient mulch layer,” Wallhead stated.
On the flipside, although, Kate Garland, horticultural specialist on the College of Maine Cooperative Extension, warned in opposition to letting an excessive amount of mulch accumulate over time, particularly in decorative gardens.
“A standard subject is thick, thick layers of mulch that accumulate on decorative gardens,” Garland stated. “Landscapers are entering into yearly and including mulch time and again with out raking off the outdated mulch.”
In case you are fearful about mulch piling up, Garland really helpful slicing wooden chips or bark mulch with compost.
“Your mulch will break down a bit of bit quicker and never accumulate as a lot,” she stated.
Watch: Natural farmer Tom Roberts shares some suggestions for spring gardens
